Obtain the number of used RBs using the cell performance monitoring function on the LMT. Then, divide the number of used RBs by the total number of RBs in the measurement period (indicated by the 1-1 column in the following figure) to calculate the cell RB usage. The maximum RB usage is 100%. The following figure shows the real-time number of RBs used by or allocated to the cell.
The total number of RBs in a measurement period can be calculated based on the subframe configuration and special subframe configuration. The period is 1000 ms by default (100 radio frames). It is recommended that the period be changed to 200 ms. The formula is as follows:
Total number of RBs = Number of downlink subframes x Number of RBs occupied by the cell bandwidth
For example, if the cell bandwidth is 20 MHz, the timeslot configuration is SA0, and the special subframe configuration is SSP7, the total number of downlink RBs in 200 ms is:
20 (radio frames) x 100 (RBs) x 4 (downlink subframes) = 8000
